This invention is directed to combines and other off-road vehicles powered by internal combustion engines, wherein one or more auxiliary power demands are periodically placed on the engine. The invention is further directed to such vehicles wherein the engine is controlled by an electronic engine control unit as part of an electronic engine control system.
Combines are large agricultural machines used to harvest grain or other crop material from supporting plants. Such harvesting of the crop material includes e.g. cutting plants containing such crop material or otherwise severing the crop material from the plant, threshing and separating the crop material from the plant material, and cleaning the crop material from the supporting plant material and other debris with which the crop material may be associated. Such combine typically has a grain tank for temporarily storing harvested crop material. The combine also has an unloading auger for unloading the crop material from the grain tank to a grain cart or truck. Combines may further be provided with additional crop processing assemblies such as straw choppers and chaff spreaders. Combines are typically embodied in self-propelled vehicles.
A typical combine uses a single engine to power all machine functions, including the various operations noted above, in addition to powering movement of the vehicle from place to place in the normal course of operation. Thus, the load on the engine varies in accord with the loads applied by the various assemblies which are activated, operated, and deactivated during routine use of the machine.
A typical such combine operates at a set engine speed. Typical combines have two or three speed settings which correspond, for example, to xe2x80x9clowxe2x80x9d speed, xe2x80x9cmediumxe2x80x9d speed, and xe2x80x9chighxe2x80x9d speed. Each of such speeds has a target engine rotation speed. For example, xe2x80x9clowxe2x80x9d speed can have a target engine speed of about 1200 rpm. xe2x80x9cMediumxe2x80x9d speed can have a target engine speed of about 1600 rpm. xe2x80x9cHighxe2x80x9d speed can have a target engine speed of about 2200 rpm.
The speed setting is set by the vehicle operator. Once the vehicle operator selects a speed setting, an electronic engine control unit (ECU) controls the engine speed according to the selected setting, primarily by dynamically adjusting the quantity of fuel injected into the engine cylinders. When the operator makes a different speed selection, the engine control unit responds by changing the quantity of fuel being injected into the cylinders, in order to maintain the engine speed at the predetermined target engine speed.
A primary task of the ECU is to dynamically maintain the engine speed constant in the face of whatever loads are being imposed on the engine. As a load is imposed which causes the engine rpm to decrease below a first predetermined speed, the engine control unit increases the quantity of fuel being injected into the cylinders, in order to increase the amount of power being developed by the engine, and thus to maintain engine speed within a target range between the first and second predetermined speeds.
Similarly, as a load is removed or decreased which causes the engine speed to increase above a second predetermined level, the engine control unit decreases the quantity of fuel being injected into the cylinders, in order to decrease the amount of power being developed by the engine, thus to maintain engine speed within the target range between the first and second predetermined speeds.
Thus, conventional engine control units respond to engine speed changes by changing the fuel flow to the cylinders in attempting to maintain engine speed within a range of predetermined engine speeds.
While the ECU thus responds reactively, step changes in engine loading can cause substantial decreases in engine speed before the engine control unit can respond to the dynamically changing situation.
U.S. Pat. No. 4,522,553 issued Jun. 11, 1985 to Nelson et al teaches boosting engine power by a predetermined amount to a fixed higher level when the unloading auger is switched on, and correspondingly reducing the engine power by a corresponding predetermined amount to a fixed lower level when the unloading auger is switched off.
However, the wide range of operating systems which consume power in the combine results in a constantly varying load demand being placed on the engine and engine drive train. To the extent multiple load demands increase simultaneously, to the extent a load demand increases step-wise by a substantial amount, the engine may become overloaded such that the engine speed drops below an acceptable speed. When the engine speed drops below such acceptable speed, engine systems such as engine cooling and lubrication can be affected so as to reduce engine wear life. In addition, the ability of the engine to sustain operation, and/or to recover to desired operating speed, when an excessive load is applied, may be jeopardized. Where an unexpected heavy load is coupled with a load change which can be predicted, the combined affect of the predictable load and the unexpected load can have a negative affect on overall engine operation, or user perception of engine operation. However, if certain load changes can be predicted and anticipated, and engine power adjusted pro-actively to such anticipated loads, the detrimental coupling affect of concurrent unexpected load increases can be lessened or avoided.
It is an object of the invention to provide an engine power control system, including an electronic engine control unit and a fuel system including a fuel supply pump and adjustment apparatus which, in combination, make incremental changes in power output of the engine in anticipation of incrementally progressive changes in load demand on the engine.
It is another object to provide an engine power control system, including an electronic engine controller and a fuel system including a fuel supply pump and adjustment apparatus which, in combination makes incremental changes in power output of the engine in anticipation of load demands on the engine, in combination with making further changes in power output of the engine in reaction to sensed engine-loading changes which are not satisfied by the anticipatory changes.
Yet another object is to provide methods of providing pro-active, anticipatory changes in inputs to engine power.
Still another object is to provide methods of providing both pro-active anticipatory changes in inputs to engine power and reactive changes in inputs to engine power in response to sensed engine-loading changes which are not satisfied by the pro-active anticipatory changes.
In this invention, an engine control unit uses a power curve or an algorithm for a power curve to pro-actively adjust fuel flow rate to an internal combustion engine, thereby to adjust engine power, in anticipation of changes in loads being imposed on the engine. In the alternative, the engine control unit can combine input from such pro-active algorithm with input from a reactive algorithm, thus to develop a combined fuel flow rate control signal to fuel injectors at the engine.
A first family of embodiments of the invention comprehends, in an engine-driven vehicle, an engine power control system controlling the power output of the engine. The engine power control system comprises a fuel system including a fuel supply pump and adjustment apparatus which adjusts the rate at which fuel is delivered to combustion chambers of the engine in response to control signals supplied to an input of the adjustment apparatus, thereby to adjust power output of the engine; and an electronic engine controller capable of generating, and delivering to the adjustment apparatus, a series of control signals which cause the adjustment apparatus to change the rate at which fuel is delivered to the combustion chambers thereby to change the power output of the engine. The electronic engine controller has at least one of a power curve or an algorithm for a power curve stored in memory which, responsive to certain predetermined operating conditions other than sensed engine speed, provides a sequence of pro-active change inputs, at predetermined rates of change, in rate of delivery of fuel to the engine combustion chambers, at points in time based on timing of occurrence of the respective operating conditions, thereby to produce pro-active incremental changes in power output of the engine. Such pro-active incremental power changes are effected in anticipation of changes in load demand on the engine, and the pro-active incremental power changes correspond generally with expected incrementally progressive changes in load demand on the engine.
In preferred embodiments, the vehicle has an auxiliary function, for example a grain unloading function, powered by the engine, the auxiliary function being capable of being operated while the vehicle is moving. The engine power control system further comprises a switch operable for activating and deactivating the auxiliary function in a step-wise manner. The stored power curve or algorithm for the power curve, in response to activation and deactivation of the switch, provides pro-active relatively greater step change inputs in quantity of fuel delivered to the engine combustion chambers, at points in time based on timing of the activations and deactivations of the switch, while simultaneously and additively providing pro-active relatively smaller incremental change inputs in quantity of fuel delivered to the engine combustion chambers at points in time based on timing of the respective certain predetermined operating conditions other than the auxiliary function. Thus, the power curve or algorithm so employed by the electronic engine controller provides an additive combination of pro-active relatively greater step change inputs, and proactive relatively smaller increment change inputs, in power output of the engine in anticipation of changing load demands on the engine.
In preferred embodiments, the power curve or algorithm is responsive to one or more real-time operating conditions selected from the group consisting of mass quantity of grain in a grain tank on the vehicle, grain tank mass fill rate, grain moisture, density of grain being received in the grain tank, and changes in slope of terrain over which the vehicle is moving.
Optionally, a second predetermined operating condition to which the power curve or algorithm is responsive comprises the auxiliary function and the auxiliary function comprises activation and deactivation of an unloading auger unloading grain from the grain tank, whereby pro-active step-wise changes in power are effected based on anticipated load changes on the engine related to starting, operating, and stopping operation of the unloading auger by operation of the switch.
In preferred embodiments, the power curve or algorithm includes
(i) a first upwardly sloping line representing a first set of small incremental increases in engine power, over a first period of time, in anticipation of increasing grain load in a grain tank on the vehicle over the respective period of time,
(ii) a second relatively greater magnitude step change increase in engine power effected in anticipation of increased load on the engine and implemented when a grain unloading auger on the vehicle is activated to unload grain from the grain tank,
(iii) a third relatively smaller, downwardly sloping line representing a second set of small incremental decreases in engine power over a second period of time, in anticipation of decreased load on the engine over a subsequent period of time while the auger is unloading grain from the grain tank, and
(iv) a fourth relatively greater magnitude step change decrease in engine power effected in anticipation of decreased load on the engine and implemented when the grain unloading auger is deactivated.
A second set of embodiments of the invention comprehends, in an engine-driven vehicle, an engine power control system controlling the power output of the engine. The engine power control system comprises a fuel system including a fuel supply pump and adjustment apparatus which adjusts the rate at which fuel is delivered to combustion chambers of the engine in response to control signals supplied to an input of the adjustment apparatus, thereby to adjust power output of the engine; and an electronic engine controller capable of generating, and delivering to the adjustment apparatus, a series of control signals which cause the adjustment apparatus to change the rate at which fuel is delivered to the combustion chambers thereby to change the power output of the engine. The electronic engine controller has at least one of a power curve or an algorithm for a power curve stored in memory. The power curve or algorithm changes quantity of fuel delivered to the combustion chambers of the engine according to a combination of
(i) a first parameter defining pro-active change inputs based on anticipated engine loading changes, and
(ii) a second parameter defining reactive change inputs responsive and reactive to sensed engine-loading changes not satisfied by the first proactive parameter.
In preferred embodiments, the vehicle has an auxiliary function powered by the engine. The auxiliary function is capable of being operated while the vehicle is moving. The engine power control system further comprises a switch operable for activating and deactivating the auxiliary function in a step-wise manner. The stored power curve or algorithm for the power curve, in response to activation and deactivation of the switch, provides pro-active relatively greater step change inputs in quantity of fuel delivered to the engine combustion chambers based on the first parameter, at points in time based on timing of the activations and deactivations of the switch, while simultaneously and additively providing pro-active relatively smaller incremental change inputs in quantity of fuel delivered to the engine combustion chambers based on the first parameter, at points in time based on timing of certain pre-determined operating conditions other than the auxiliary function. Correspondingly, the power curve or algorithm so employed by the electronic engine controller provides an additive combination of pro-active relatively greater step change inputs based on the first parameter, proactive relatively smaller increment change inputs based on the first parameter, and reactive change inputs based on sensed engine-loading, in dynamically controlling power output of the engine.
A third family of embodiments are implemented in methods wherein, in an engine-driven vehicle wherein an engine power control system comprises a fuel system including a fuel supply pump and adjustment apparatus which adjusts the rate at which fuel is delivered to combustion chambers of the engine in response to control signals applied to an input of the adjustment apparatus, thereby to adjust power output of the engine, the vehicle including an electronic engine controller capable of generating, and delivering to the adjustment apparatus, a series of control signals which cause the adjustment apparatus to change the rate at which fuel is delivered to the combustion chambers thereby to change the power output of the engine, the electronic engine controller having at least one of a power curve or an algorithm for a power curve stored in memory, effective to control fuel input to the engine, a method of controlling power output of the engine. The method comprises providing a sequence of pro-active change inputs of progressively changing magnitude, in quantity of fuel delivered to the engine combustion chambers, at points in time based on timing of occurrence of the respective operating conditions, thereby producing pro-active changes, of progressively and incrementally changing magnitude, in power output of the engine in anticipation of expected changes in load demand on the engine, and which pro-active power output changes generally correspond with expected progressive changes in load demand on the engine.
In some embodiments, the vehicle has an auxiliary function powered by the engine. The auxiliary function is capable of being operated while the vehicle is moving. The engine power control system further comprises a switch operable for activating and deactivating the auxiliary function in a step-wise manner. The method further comprises, in response to activation and deactivation of the switch, providing pro-active relatively greater step change inputs in quantity of fuel delivered to the engine combustion chambers, at points in time based on timing of the activations and deactivations of the switch, while simultaneously and additively providing pro-active relatively smaller incremental change inputs in quantity of fuel delivered to the engine combustion chambers at points in time based on timing of the respective certain determined operating conditions other than the auxiliary function. Thus, the invention provides an additive combination of pro-active relatively greater step change inputs, and proactive relatively smaller increment change inputs, in power output of the engine in anticipation of changing load demands on the engine.
The method preferably includes sensing slope of terrain immediately ahead of the vehicle, and providing, as a component of the pro-active change inputs, a change increment responsive to the sensed slope of the terrain.
Other embodiments of the invention are implemented in methods wherein, in an engine-driven vehicle wherein an engine power control system comprises a fuel system including a fuel supply pump and adjustment apparatus which adjusts the rate at which fuel is delivered to combustion chambers of the engine in response to control signals applied to an input of the adjustment apparatus, thereby to adjust power output of the engine, the vehicle including an electronic engine controller capable of generating, and delivering to the adjustment apparatus, a series of control signals which cause the adjustment apparatus to change the rate at which fuel is delivered to the combustion chambers thereby to change the power output of the engine, the electronic engine controller having at least one of a power curve or an algorithm for a power curve stored in memory, effective to control fuel input to the engine. The method comprises providing a sequence of change inputs, in quantity of fuel delivered to the engine, according to a combination of
(i) a first parameter defining pro-active change inputs based on anticipated engine loading changes, and
(ii) a second parameter defining reactive change inputs responsive and reactive to sensed engine loading changes not satisfied by the first pro-active parameter.
In preferred embodiments, with an auxiliary function powered by the engine, and capable of being operated while the vehicle is moving, the engine power control system further comprises a switch for activating and deactivating the auxiliary function in a step-wise manner. The method further comprises, in response to activation and deactivation of the switch, providing pro-active relatively greater step change inputs in quantity of fuel delivered to the engine based on the first parameter, at points in time based on timing of the activations and deactivations of the switch, while simultaneously and additively providing pro-active relatively smaller incremental change inputs in quantity of fuel delivered to the engine combustion chambers based on the first parameter at points in time based on timing of the respective certain determined operating conditions other than the auxiliary function, thereby providing an additive combination of pro-active relatively greater step change inputs based on the first parameter, proactive relatively smaller increment change inputs based on the first parameter, and reactive change inputs based on the second parameter of sensed engine-loading, in dynamically-controlling power output of the engine.